1. Field of the Invention
The present invention relates to a technique of forming an image, and more particularly to a technique of correcting the property of an image to be formed.
2. Description of the Related Art
There are each known as an apparatus for forming an image, an inkjet printer, a laser printer, etc. The laser printer is classified into a monochrome laser printer for printing a monochrome image, a color laser printer for printing a multi-color image, etc.
In general, the above color laser printer is configured, such that a photoconductor is exposed to a laser beam, to thereby form on the photoconductor an electrostatic latent image corresponding to a visible image to be eventually formed, such that toner is then attached to the formed electrostatic latent image for development thereof, and such that the developed image is transferred by way of an intermediate transfer medium onto an print sheet of paper, resulting in the formation of the visible image on the print sheet.
The printings using the above laser printer require the photoconductor to be rotated. Possible variations in speed of the photoconductor in rotation, temporal deterioration of movable components of the laser printer due to friction thereof, etc. may therefore result in unexpected variations in position of an image printed on a print sheet.
In addition, toner, which is used for development of the electrostatic latent image, is varied in ability of the toner to be attached to such as the photoconductor, due to change in the ambient environment (e.g., room temperature, humidity, etc.) and temporal deterioration of the toner itself. These may therefore result in errors in density of an image printed.
To eliminate the above potential disadvantages, a conventional laser printer is configured, such that, at the initiation stage of a printing operation of the printer, or after printings for a predetermined number of sheets of paper are completed, a predefined test pattern is formed on the photoconductor and the intermediate transfer medium, such that the density and the position of the test pattern formed are detected, and such that, based on the detection results, corrections are made to the density and the position. This is disclosed by Japanese Patent Publication No. Hei 11-258872.